Older patients with persistent and progressive symptoms of chronic back pain and leg pain often have a diagnosis of lumbar degenerative spondyolisthesis and undergo complex lumbar decompression and fusion surgery. Over 300,000 of these procedures are performed in the United States each year. Surgery is highly effective but technically challenging. One technical challenge of fusion in spondylolisthesis is that after decompression, there may not be much bone left on the posterior surface of vertebrae for bone graft placement. Therefore, to improve bone healing, surgeons also perform an ?interbody fusion? across the intervertebral disk space between the vertebral bodies. This part of the surgery requires manipulating nerve roots, which may be injured, leading to new leg pain after surgery in 5% to 15% of the patients. A surgical technique that requires less or no manipulation of the nerve roots may avoid these poor outcomes. We have developed a drill that creates a cavity across the intervertebral disc space through a small access bore without requiring nerve root manipulation. The cavity can then be filled with bone graft materials to allow fusion. However, the drill currently requires manual positioning and control by the surgeon. Slight malposition could lead to a catastrophic injury of nearby vital structures, including spinal nerves (i.e., paralysis) and large blood vessels (i.e., sudden bleeding and death). Most modern surgical suites can now be equipped portable fluoroscopy based CT scanners. There is an opportunity to develop novel imaging and computer driven surgical tools that enable surgeon to perform previously unthinkable complex surgeries. With these changes in the surgical environment, we have resurrected our old cavity creation drill with sensors that detect the drill?s position, torque and electrical resistance. We have developed an anchoring mechanism that tightly attaches the drill to the vertebrae, while preventing the bones from moving. We have also developed precise computer control of drill activation and linear displacement. We are requesting funding to allow refinement of the prototype ?smart? drill for use in a sterile surgical environment and conduct in vitro validation in harvested human cadavers. Senior orthopedic surgery and neurosurgery residents will train to use the device and then perform procedures on harvested pig lumbar spine specimens. We hypothesize that the ?Smart Cavity Creator? drill will allow surgeons to precisely control the size and location of the intervertebral cavity to exactly match the preoperative plan and have no failures (i.e. no violation of vertebral body cortical margins). SBIR funding for prototype refinement and in vitro validation will accelerate development of this potentially disruptive technology. Eventually, this method could lead to a new technique for lumbar interbody fusion with less morbidity.